Three cases of extensive bone marrow necrosis in patients with sickle cell disease are reported. All three patients presented severe bone pains with severe anaemia (haemoglobin value less than 5 g/dl) and high increased of LDH serum values (upper than 20 fold normal value). Bone marrow aspirate and biopsy showed typical signs of necrosis. The extent of necrosis was evaluated by reticuloendothelial scan obtained with 111In chloride. Treatment required transfusions of phenotyped red blood cell concentrates. Favourable outcome was observed in all patients.